Process of heating fuel in tank and upon withdrawal

ABSTRACT

A method for heating fuel by a fuel heater formed from an elongated unitary structure which defines a fuel channel passing through the length thereof and which defines in the bottom thereof a fuel intake. The unitary structure also defines a heating fluid inlet and outlet on one side of the fuel channel which communicate with one another on that one side of the fuel channel.

This application is a continuation of application Ser. No. 07/467,887,filed Jan. 22, 1990 now U.S. Pat. No. 5,029,634 filed Sep. 9, 1991.

BACKGROUND OF THE INVENTION

This invention relates generally to the art of heat exchange and moreparticularly to an apparatus for heating fuel within a fuel tank.

Diesel fuel operated vehicles have proven to be a great boom totransportation because of their ability to operate economically andefficiently; particularly as compared to gasoline operated vehicles. Arecurring problem with the operation of diesel fuel poweredtransportation, however, is the affect of extremely cold temperatures ondiesel fuel. In extremes of cold, diesel fuel has a tendency to gel thusmaking engine operation difficult if not at times impossible. Theinventor herein has contributed to devices to alleviate this problem.References are made to U.S. Pat. Nos. 3,929,187 and 4,624,779 and U.S.application Ser. No. 07/309,105 of Feb. 13, 1989.

Several prior art heaters have employed devices which are placed incontact with fuel in the tank for warming the fuel in the tank.

One such device is described in U.S. Pat. No. 4,726,636 to Lucht whereina heating apparatus is passed into the fuel tank opening and is adaptedto fit thereover. An additional apparatus is disclosed in U.S. Pat. No.4,656,979 to Hoganson wherein an apparatus is placed through an openingin a fuel tank into the fuel and then extends transversely along thebottom of the tank, like a foot, for directly warming the fuel along thebottom of the tank. The above referenced patent to Lucht discloses asimilar foot extending transversely within a fuel tank.

U.S. Pat. No. 4,749,960 to Gilbert Wolf discloses an apparatus forintank fuel warming wherein an outlet is partially surrounded by aheating jacket through which a heating fluid is passed. The Wolf patentalso discloses a foot type structure.

While these prior art structures have operated somewhat satisfactorilyto warm fuel, additional improvements, particularly with regard tointank fuel heaters, are required to render such devices more effective,durable and resistent to vibration and fuel movement.

SUMMARY OF THE INVENTION

It is thus an object of this invention to provide a novel intank fuelheating apparatus.

It is a further object of this invention to provide such an intank fuelheating apparatus which is resistent to vibration and fuel movement.

It is thus a further and more particular object of this invention toprovide such an apparatus which is small enough to be placed through afuel gauge opening of a fuel tank to render unnecessary the placement ofan additional opening through a fuel tank.

It is a further and yet more particular object of this invention toprovide such an apparatus which has a fuel outlet and heat transfermedium passageway formed from a unitary structure and which actuallyheats rather than warms fuel as it is removed from the tank.

These as well as other objects are accomplished by an intank fuel heaterformed from an elongated unitary structure which defines a fuel channelpassing through the length thereof, and which defines in the bottomthereof a fuel intake. The elongated unitary structure defines a heatingfluid inlet and outlet both of which extended the length of theelongated unitary structure on one side of the fuel channel and whichcommunicate with each other on that one side of the fuel channel nearthe fuel intake. Heating fluid in the inlet and outlet heats fuelthrough the entire length of the fuel channel as well as heating fuelsurrounding and beneath the unitary structure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 of the drawings is a partial cutaway perspective view of a fueltank having the apparatus of this invention mounted therein.

FIG. 2 of the drawings is an enlarged partial cutaway view of the fuelheater of this invention.

FIG. 3 of the drawings is a cross sectional view along the line 3--3 ofFIG. 2.

FIG. 4 is a cross sectional view along the line 4--4 of FIG. 3.

FIG. 5 is a partial cutaway view along the line 5--5 of FIG. 3.

FIG. 6 is a top view of FIG. 2.

FIG. 7 of the drawings is a cross sectional view similar to FIG. 2illustrating an additional embodiment of this invention.

FIG. 8 of the drawings illustrates in a perspective view an adapterplate in accordance with this invention.

DETAILED DESCRIPTION

In accordance with this invention it has been found that a unitarystructure may be utilized to produce an intank fuel heater havingdimensions significantly less than any intank fuel heater previouslyutilized. Such lesser dimensions permit the apparatus to be mounted in aconventional fuel gauge opening within a fuel tank while simultaneouslylessening forces that are applied to that opening due to the smallersize of the apparatus exposed to the fuel. Because it is an unitarystructure vibration effects are minimized. Various other advantages andfeatures will become apparent from a reading of the followingdescription given with reference to the various figures of the drawings.

FIG. 1 of the drawings illustrates a fuel tank 1 having fuel 3 thereinand the intank fuel heater 5 of this invention mounted therethrough. Onthe exterior of tank 1 the apparatus 5 of this invention has an opening7 to communicate with a source of heat transfer medium and an opening 9to permit exit of that heat transfer medium. The heat transfer medium ispreferably the heat transfer medium utilized in a engine, such that theheat from the engine is utilized to heat fuel as it leaves the apparatus5 through a fuel line 11.

FIG. 2 of the drawings is a partial cutaway view of the apparatus 5 ofthis invention. It is seen that the apparatus 5 is formed of anelongated unitary structure 21 which defines therein a fuel channel 23which extends the entire length of the elongated unitary structure 21.The heat transfer medium which enters through opening 7 and exitsthrough opening 9 is utilized to heat the fuel which is within the fuelchannel 23 by means best illustrated in FIG. 3 which is a crosssectional view along the line 3--3 of FIG. 2. Referring to FIG. 3 it isseen that elongated unitary structure 21 defines on one side of the fuelchannel 23 a heat transfer fluid channel inlet 25 and heat transfermedium outlet 27. It is understood that terms "inlet" and "outlet" arefor the purpose of reference only since the heat transfer medium canflow in either direction.

It should be noted from FIG. 3 that inlet 25 and outlet 27 are locatedon one side of elongated unitary structure 21, while the fuel channel 23is located on an opposite side of structure 21. This arrangement permitsthe overall diameter of the unitary structure 21 to be maintained at aminimum and permits heat transfer to occur effectively within a smallspace. It is seen that inlet 25 and outlet 27 are largely kidney shapedwith the interior kidney surface 31 and 33 focused toward fuel channel23 and the outer kidney surface 35 and 37 focused toward outer surface39 of elongated unitary structure 21.

Fuel channel 23 itself has a serrated fin surface to provide a largeheat transfer surface within the fuel channel 23. Elongated structure 21with its various openings therethrough is preferably formed by ametallic extrusion process and preferably formed of a metallic materialhaving high heat transfer coefficients such as aluminum and aluminumalloys.

Inlet 25 and outlet 27 communicate with one another through a passageway41, best illustrated in FIGS. 2 and 4. Passageway 41 is located nearfuel intake opening 43 of fuel channel 23.

Since unitary structure 21 is an extrusion, channel 41 is preferablymachined therein and closed off by a plug structure 45. Fuel intake 43may be better viewed from FIG. 5 which is a cross sectional view alongthe line 5--5 of FIG. 3. It is, of course, understood from a view ofFIGS. 3, 4, and 5 that heat is provided through the bottom 46 of unitarystructure 21 to heat fuel before it enters fuel intake 43. This is incontrast to prior art intank heaters which do not provide heat throughthe bottom thereof.

Referring to the lower end of FIG. 2 which is a cross section generallyalong the line 2--2 of FIG. 3, passageway 41 is illustrated as itcooperates with inlet 25 and outlet 27 showing the flow of heat transfermedium by arrow 51 about one side of the elongated unitary structure 21.

It is indeed seen that the apparatus of this invention provides heat tothe fuel in fuel channel 23 from the bottom of elongated structure 21 tothe top thereof, i.e. from the fuel intake opening 43 to the fuel outletline 11.

Referring to the upper section of FIG. 2, a portion of fuel tank 1 isillustrated as having an opening 61 therein, which is the same size asthe standard opening for a fuel gauge. An adapter plate 63 is bolted tothe fuel tank through standard openings and is rotatably attached toupper head 65 which is sealed to elongated unitary structure 21 byo-ring 64 and secured thereto by bolts 67 and 69 as well as bolts 71which are illustrated in the top view of FIG. 6. Clamp ring 81 assistsin maintaining the integrity of the mounted structure.

An additional embodiment is illustrated in FIG. 7 wherein a fuel tankmounts the apparatus of this invention through an opening the same sizeand cost but not otherwise adapted for a fuel gauge. In this event thefuel tank 1 has mounted therebelow a lower adaptor plate 91 better seenin FIG. 8. Lower adapter plate 91 is horseshoe shaped with an open endportion to facilitate placement of the lower adapter plate 91 within afuel tank opening having a diameter the same size as the inner diameterof the horseshoe shaped lower adapter plate 91. Lower adapter plate 91has a leg 93 temporarily attached thereto to maintain placement within afuel tank while adapter plate 63 is secured to lower adapter plate 91 byillustrated bolts 95 and 97, as well as others not shown. Leg 93 isloosely secured so to that it can be manually removed after loweradapter plate 91 is secured.

An advantage of the configuration whereby adapter plate 63 is secured toupper head 65 by a clamp 81 so that the mounting is rotatable. Sincerotation assures a desired orientation for unitary structure 21,appropriate alignment with fuel line 11 is easily achieved. Uponachieving appropriate orientation clamp 81 is secured and bolts 67, 69and 71 tightened.

The apparatus of this invention has significant advantages. It is easilyinstalled within a fuel tank of either an original piece of equipment orin the after market because of the bolting arrangement. The boltingarrangement is compatible with that of original equipment fuel gauges aswell as including an adapter plate having a similar configuration forindependent mounting in the after market. The easy installation of theapparatus of this invention also permits rotatable orientation duringthe installation process. The apparatus of this invention heats fuelthrough the entire length of an elongated structure as well as heatingthe bottom thereof to provide heat to the fuel in the tank. Heat istransmitted from the apparatus of this invention through the entirecircumference thereof as well as the entire length.

With this heater in each fuel tank, it is now possible to run dual drawand dual return fuel systems in cold weather, therefore, eliminatingcross over hoses, bottom draw and standard draw tubes and thereforeeliminating fuel spills on highways from broken cross over lines.

It is thus seen that the apparatus of the invention provides an intankfuel heater which is more resistent to vibration and fuel movement thanintank fuel heater devices previously utilized. It is further seen thatthis invention provides an intank fuel heater of lesser dimensions thanthose previously provided and which is insertable into a fuel tankthrough a conventional fuel gauge opening. It is further seen that thisinvention provides an intank fuel heater formed of a unitary structure.As various modifications will become apparent to those of skill in theart from a reading of the foregoing specification which is exemplary innature, such modifications are embodied within the spirit and scope ofthis invention as defined by the following appended claims.

That which is claimed:
 1. A process for heating fuel as it is removedfrom a tank thereof comprising the steps of:immersing an elongatedstructure in said fuel; drawing said fuel through an intake of saidelongated structure, said elongated structure having a bottom definingsaid intake and outer walls contacting said fuel said bottom including agenerally planar plug structure adjacent the portion thereof definingsaid intake, said plug structure having an interior surface and anexterior surface coplanar with said intake; passing a heating fluiddownwardly through said elongated structure adjacent said drawn fuel onthe exterior thereof to heat said drawn fuel and heat fuel adjacent saidouter walls on the exterior thereof; continuing to pass said heatingfluid downwardly to said interior surface of said plug structure to heatsaid plug structure and the exterior surface thereof and thereby heatsaid fuel immediately adjacent said bottom and near said intake prior tosaid fuel entering said intake; reversing the flow of said heat transferfluid at said interior surface; and passing said heat transfer fluidupwardly adjacent said drawn fuel whereby said heat transfer fluid heatssaid fuel along substantially entire length of travel of said fuelthrough said elongated structure.